ORIGINAL: Soilarch
You might try to find some Federal Tru-ball slugs. They're kinda new and heard about them when I was doing research on sabot slugs. It's still designed for smoothbores but brings a new design to the table.
definetly agree with this, I read an article last year on them, and the shooters were really impressed with the groups they got. Mount a scope on your 12 guage, & with these slugs, and you got a real leathal combo!